The fuller the bottle & colder it's kept - the longer it'll last. Buy some wine in 1/2 bottles (.375) & keep the bottles. You want 2 glasses ? Fill up the 375 & put it in the fridge. It'll last weeks at least. Pour in boiling water & let it sit for awhile between uses. Wine can also be frozen to stop the oxidization. If a wine is not going to be consumed, I'll freeze it and use it for cooking, whenever. I've even pulled wine out of the bottom of the freezer that had been there for years & it was still quite palatable. wj